Overview
Protects against Japanese encephalitis virus, a mosquito-borne disease causing brain inflammation, found across Asia and parts of northern Australia.
Recommended for travellers spending 1 month or more in endemic areas during the transmission season, particularly in rural or agricultural areas. Consider for shorter trips if outdoor or nighttime exposure is significant. Added to the NIP in 2023 for residents of high-risk areas in Australia following the 2022 domestic outbreak.
Vaccination Schedule
Standard schedule: Imojev: single primary dose for adults and children aged 9 months and older. Booster dose recommended at least 1-2 years after primary dose if ongoing risk.
Accelerated schedule: No accelerated schedule. Single dose provides primary protection.
Route: Subcutaneous injection
Brands Available in Australia (TGA-Registered)
- Imojev (Sanofi)
Cost in Australia
Estimated cost: $250-$350 per dose
Medicare/PBS: Funded under NIP since March 2023 for people living in, or travelling to, areas of Australia at higher risk of JE virus (parts of NSW, VIC, QLD, SA, WA, NT). Not funded for international travel purposes. Available on private prescription.
Efficacy & Duration
Efficacy: Greater than 95% seroprotection after a single dose
A single dose of Imojev induces neutralising antibodies in more than 95% of recipients within 28 days. Seroprotection rates remain high for at least 5 years, though a booster is recommended at 1-2 years for those with ongoing exposure risk.
Duration of protection: Protection likely lasts at least 5 years after primary dose. Booster recommended at 1-2 years for ongoing risk. Long-term duration still under study.
Side Effects
| Side Effect | Frequency |
|---|---|
| Injection site pain, tenderness | Very common (>50%) |
| Headache, fatigue, myalgia | Common (10-50%) |
| Fever, nausea | Uncommon (1-10%) |
| Rash | Uncommon (1-10%) |
Contraindications
- Severe allergic reaction to a previous dose or vaccine component
- Immunocompromised individuals (live vaccine)
- Pregnancy (live vaccine, defer until after delivery)
- Breastfeeding (defer if possible; limited data)
- Children under 9 months of age
- History of thymus disorder (thymoma, myasthenia gravis) or thymectomy
Special Populations
Pregnancy
Contraindicated during pregnancy. Imojev is a live vaccine. Women should avoid pregnancy for 28 days after vaccination.
Children
Licensed from 9 months of age. Same dose as adults. For children aged 9 months to under 18 years, a booster is recommended 1-2 years after the primary dose if ongoing risk.
Immunocompromised Travellers
Contraindicated in immunocompromised individuals as Imojev is a live chimeric vaccine. This includes persons on immunosuppressive therapy, those with primary immunodeficiency, and HIV-positive individuals with CD4 count below 200 cells/microlitre.
Frequently Asked Questions
Do I need Japanese encephalitis vaccine for South-East Asia?
It depends on your itinerary. JE vaccine is recommended if you are spending a month or more in rural areas of South-East Asia, particularly during the wet season. Short-stay urban travellers are at lower risk, but consider the vaccine if you will be near rice paddies, pig farms, or doing extensive outdoor activities.
How much does the Japanese encephalitis vaccine cost?
Imojev costs approximately $250-$350 per dose in Australia. It is one of the more expensive travel vaccines. It is funded under the NIP for residents of high-risk areas within Australia but not for international travel.
Is Japanese encephalitis found in Australia?
Yes. Japanese encephalitis virus was detected in pigs and humans across eastern Australia in 2022, leading to a national emergency response. The NIP was expanded in 2023 to fund vaccination for people in high-risk areas across NSW, VIC, QLD, SA, WA, and NT.
How many doses of JE vaccine do I need?
Imojev requires only a single primary dose. A booster is recommended 1-2 years later if you continue to travel to or live in endemic areas. This is simpler than the older JE vaccines which required multiple doses.
Can immunocompromised people get the JE vaccine?
No. Imojev is a live vaccine and is contraindicated in immunocompromised individuals. This includes people on immunosuppressive medications, those with HIV and a low CD4 count, and those with certain thymus conditions. Discuss alternative protective measures with your doctor.
Is Japanese encephalitis vaccine safe during pregnancy?
Imojev is contraindicated during pregnancy because it is a live vaccine. If you need JE protection and are pregnant, discuss the risks and benefits with your specialist. Mosquito bite prevention is the main protective measure for pregnant travellers.
What is the risk of getting Japanese encephalitis?
The risk for most short-term tourists is very low (less than 1 in a million). However, the disease is severe when it occurs: approximately 20-30% of cases are fatal and 30-50% of survivors have permanent neurological damage. The vaccine is recommended as a precaution for higher-risk travellers.
Can I get the JE vaccine at the same time as other travel vaccines?
Imojev can be given at the same time as inactivated vaccines (such as Hepatitis A, typhoid injection). However, it should be given at least 28 days apart from other live vaccines (such as MMR or yellow fever) unless administered on the same day.
Sources & References
Last updated: April 2026